Magnetic transducer technology finds application in the measurement of torque and position. It has been especially developed for the non-contacting measurement of torque in a shaft or any other part being subject to torque or linear motion. A rotating or reciprocating element can be provided with a magnetized region, i.e. a magnetic encoded region, and when the shaft is rotated or reciprocated, such a magnetic encoded region generates a characteristic signal in a magnetic field detector (like a magnetic coil) enabling to determine torque or position of the shaft. Such kind of sensors are disclosed, for instance, in WO 02/063262.
WO 05/064301 discloses another torque sensor based on a magnetic sensor principle and is based on the application of current pulses directly to a shaft, the pulses being defined by a steep raising edge and a slow falling edge.
U.S. Pat. No. 6,810,754 discloses a transducer for measuring displacement comprising a transducer assembly in which there is a coil wound about an axis and energizable to generate a magnetic field, and first and second magnetic field sensor devices, that are axially spaced with the coil therebetween, each device being in proximity to the coil to respond to a magnetic field component generated by energization of the coil. A ferromagnetic member is disposed to interact with the field generated by the coil, the ferromagnetic member and the transducer assembly being mounted for relative displacement in the direction of said axis, such that the balance of the respective field components sensed by the first and second sensor devices is a function of the axial position of the ferromagnetic member relative to the transducer assembly.